People on waiting lists for operations are increasingly funding the procedures themselves, by getting loans from credit unions or by raising money from family members.

Up to 10pc of procedures are self-funded by people on waiting lists who do not have health insurance.

A number of credit unions have launched special loan products to fund the cost of members paying for operations and other procedures in private hospitals.

Some of these are run in conjunction with private hospitals.

Around 175,000 fewer people have health insurance since the economy went into a tail-spin in 2008, despite the fact that the number with cover has begun to creep up again.

Private hospitals carry out around 250,000 theatre procedures a year, and three million diagnostic tests, mostly funded by health insurers.

A hip replacement typically costs €12,000, with a cataract operation likely to cost around €2,500.

At least three credit unions are now offering special loans tailored to enable members to pay for operations and other treatments in private hospitals.

Whitfield Clinic in Waterford launched a pilot project with Waterford Credit Union which is offering loans for health procedures.

Chief financial officer of Whitfield, Conor McGovern, said the scheme had generated a lot of interest and would be rolled out fully this year.

Mr McGovern estimates that around 3,000 people paid for their own procedures and tests at Whitfield last year.

Lucan Credit Union in Dublin has linked up with the Hermitage Clinic to offer loans at a rate of 9.49pc for members who want to pay directly for a procedure.

But manager Paula Maguire said the 19,500-member credit union was disappointed with the take-up of the health loan offer.

Terms of five to six years can be put in place for repayments.

St Anthony's and Claddagh Credit Union in Galway city offers health loans at a special interest rate of 6.5pc, for amounts up to €40,000. Orthopaedic surgery is often funded with a loan from the credit union.

Other credit unions are understood to be considering launching health loans.

Representative body, the Irish League of Credit Unions, says it does not have detailed figures on the number of members borrowing to fund a health procedure.

Many borrow to fund dental work, which is often not covered on most health insurance policies.

But it is understood some credit union borrowers may be masking loans for a hospital treatment as a home improvement or holiday loans as they fear they will not get approval for a loan for a much-needed, life-saving procedure.

Director of the Independent Hospitals Association of Ireland, Simon Nugent, estimates that up to 10pc of the procedures and diagnostic tests carried out in the 19 hospitals in his organisation are paid for directly by patients.

Typically people get a loan from a credit union or family members club together to pay for a cataract operation for their mother who has been on a public hospital waiting list for years.

"Self-pay is a feature of the market, but not a very substantial feature of the market," he said. "We don't have specific figures, but I would estimate that self-pay is less than 10pc of the turnover of private hospitals."

He added that private hospitals and clinics were seeing a "slight uptick" in people paying directly themselves for procedures.

"Families often get together to fund a hip operation for their mother because the waiting lists in public hospitals puts them under a lot of pressure. Health insurance is not the only way to fund medical procedures," said Mr Nugent.

According to health insurance broker Dermot Goode, of TotalHealthCover.ie, people with no health insurance are often forced to borrow to pay for the likes of MRI scans which can cost €500.

As public hospital waiting lists get longer, more people are expected to be pushed into borrowing to pay for much-needed operations, those spoken to for this article agreed.